Bowser attacks the Mushroom Kingdom during the yearly Sticker Fest holiday. His attack breaks the Sticker Comet into six pieces called the Royal Stickers. Mario has to find the six Royal Stickers to restore the Sticker Comet and bring peace to the Mushroom Kingdom.

In Paper Mario: Sticker Star, Mario uses stickers to battle enemies. Stickers can be found in various areas throughout the Mushroom Kingdom. Mario has to pull them off to add them to his album of stickers.